This invention relates to pumps, and particularly to an improved two-cylinder oilless air compressor.
A common form of air compressor employs a wobble piston driven by an electric motor. Examples are found in U.S. Pat. No. 3,961,868 issued Jun. 8, 1976, for "Air Compressor", 3,961,869 issued Jun. 8, 1976, for "Air Compressor", and 5,006,047 issued Apr. 9, 1991, for "Compressor With a Segmented Piston Rod Assembly", all of which are owned by the assignee of this invention.
The wobble pistons of such air compressors have a peripherally extending seal which mates with the bore of the cylinder. No lubricant is required between the piston head and the cylinder bore. However, the movement of the piston seal in the cylinder bore generates considerable heat which must be dissipated.
Two-cylinder, in-line oilless piston compressors are also known. In one form, the two cylinders are arranged at opposite ends of a motor having a through drive shaft that mounts a wobble piston on each end. Each cylinder has a valve plate with flapper intake and exhaust valves mounted opposite the piston head. A cylinder head with intake and exhaust chambers is mounted on each cylinder and provides inlet and outlet chambers to the cylinders. The inlet and exhaust chambers of the cylinder heads are typically connected by separate tubes. Examples of the two-cylinder, in-line compressors are the 2600 series of compressors of Thomas Industries, Inc., the assignee of this invention.